Medical electric lamp



net. 1, 1929; w. H. CLIFFORD 1,729,609

MEDICAL ELECTRIC LAMP Filed Sept. 21, 1928 2 Sheets-Sheet l w I NVENTOR' Q War/1e Oct. 1, 1929. w. H QLIFFORD 1,729,609

MEDICAL ELECTRIC LAMP Filed Sept. 21. 1928 {Sheets-Sheet 2 W INVEIVITOR E f f .11 42%,,

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Patented Oct. 1, 1929 UNITED STATES PATENT OFFICE WILLIAM. HUGH CLIFFORD, F EALING, LONDON, ENGLAND MEDICAL ELECTRIC LAMP Application filed September 21, 1928, Serial No. 807,503, and in Great Britain October 14, 1927.

This invention relates to medical arc lamps, cross member slotted at each end at the and its object is to improve that known type top at 6 and at the bottom at 7. Vithin the of lamp in which the electrodes are carried tube 5 at each side, slides a member 8 of cirhorizontally on brackets which can be fed cular section with wings 9, 10 fitting respec- 5 along on cross members at the top of a standtively in the slots 6 and 7 The members 8 ard. can be fed independently by screws 11, 12

An object of the invention is to protect the which are preferably of opposite hand, and eyes of the operator from dangerous radiacarry operating heads 13, 1a. The caps 38 tions from the are or like source. which form bearings for the screws 11, 12,

10 According to this invention in a lamp of the are screwed on to the ends ofthe tube 5, while type having a tubular cross member carrying a washer 37 is interposed between the cap and the electrodes and nuts sliding in the tube, the shoulder on the screw to prevent conthe electrode carrying members are guided traction of the tube due to the presence of on the cross member by means independent the slots, and consequent possible slipping of 15 of the nuts. The lamp is provided with a the cap. cover over the upper part in the form of a On the outside of the tube 5, two tubular roof with sloping sides arranged to cut off members 15 are provided, the tubes being a lateral and upward radiations without intergood sliding fit and secured to each of the cepting radiation in the desired direction. It members 8 by screws 16 entering the wings 20 is usually unnecessasry for it to out off down- 9, 10. At the inner ends of the members 15 wardly inclined rays. are formed or secured uprights 17 to which Where the cover is of metal and any part are secured insulating members 18. At the liable to come into contact with live parts upper ends of the members 18 are secured of the lamp, such parts are provided with metal half clips 19 provided with terminals 25 insulating coverings. The cover may also 20 to receive the cables for feeding the arc, be provided with windows glazed with maand to which are hinged spring jaws 21 which terial adapted to transmit light rays but to with the half clips 19 form the complete clips out off the harmful rays. For example for taking the electrodes. To insert the Crookes glass, or fairly deep coloured glass electrodes the jaws 21 are opened by depress- '30 may be used. Preferably, the cover is proing the tails 22 against the springs 23. Such 0 vided with a light trapped outlet at the top clips will of course accommodate electrodes to permit free air circulation. varying considerably in size, while owing to An embodiment of the invention is illusthe length of the tubular members 15 the clips trated by way of example in the accompanycan support the electrodes quite close to the i 35 ing drawings, in whichare and the intermediate metal rods formerly 35 Figure 1 is a front view, partly in section, used as electrode holders, which could only of the complete lamp, with the cover reflector take one definite size of electrode are no longer and screen removed. required. Furthermore, the provision of dou- Figure 2 is a perspective view of the lamp. ble wings on the members 8 prevents any 0s- 4 Figure 3 is a plan view of the cover alone, cillation about the axis of the tube 5 and the d length of the tubular members 15 which form Fi r 41 a ectional iew on the line I-I the guiding means for the electrode carrying of Figure 1. members prevents oscillation about the other A tripod 1 as shown or alternatively aheavy two axes at right angles so that the electrodes 45 base, carries a tubular standard 2 in which are always malntained accurately in aligncan slide an upper tube 3, on which a collar ment- 11 which can be clamped by a set screw 4, for In order to form the rays emitted by the adjustment in height, while allowing tube are into a beam, I provide a reflector 24 and 3 to rotate freely within the tube 2. At the also a frame 25 in which slides a filter screen upper end of the tube 3 is secured a tubular 15 by which undesirable rays, such as heat,

may be filtered off from the beam. The reflector and frame are adjustably carried on a square section bar 26 which passes through the centre of, and is secured to, the tube 5.

The electrode holders, reflector and filter screen are enclosed in a cover made up of sheet metal with a fiat top 51 and symmetrically inclined sides 52. The rear end is closed by a plate 53 and carries a block 54 drilled to slide easily on the upright rod 55 which carries the reflector 24 and provided with a looking screw 56. The plate 53 is cut away at 57 to clear the block 58 carrying the lamp refiector 24.

At the lower edges of the sides 52, which are liable to come into contact with the electrode holders on the supports 60 during adjustments, insulators 61 are secured in any convenient manner. For example they may be grooved to receive the edges of the sides 52.

The top 51 is centrally perforated and provided with a lighttrapping cover 62. The sides are also perforated and the openings provided with guides 63 which receive plates 6% of Crookes or coloured glass which are secured by turn buttons 65.

. To catch the ash from the are I provide a tray 27 having an inturned rim to prevent spilling when tilted, beneath the cross tube 5. The tray is conveniently secured by clamping between the parts of the tube 3 which is cut through at 28 and screwed on to a nipple 29.

In order to enable the direction of the beam to be changed, the tube 3 is provided with an articulated joint with its axis parallel with the axis of the tube 5. The joint is conveniently made by forming a flat disc 30 on the upper part, and a flat coacting disc 31 on the lower part of the tube 3. The two discs are resiliently pressed together by a spring 32 on a spindle bolt 33. A wing nut 3% allows the pressure to be adjusted so that the upper part of the tube 3 can be swung sufliciently easily about the bolt 33, while the friction is sufficient to maintain the position to which the joint has been set. Clamping and unclamping to adjust the oint are therefore unnecessary. For convenience in operation, the disc 30 is provided with a handle 35.

In order that the whole lamp may be readily moved about, the main standard is provided with a handle 36. As the complete lamp is fairly heavy and it is essential that it should be held substantially vertical during move ment in order to prevent spilling of ash or risk of breakage ofthe screen, the handle is directed horizontally so that the hand occupies the most effective and natural position when the standard is vertical and there is no tendency for the whole to tilt over when it is lifted.

What I claim is 1. A medical arc lamp comprising a standard, an electrode support mounted at the top of said standard, electrode carrying members slidably mounted on said support, a cross bar on said standard set at right angles to said support, a reflector mounted at one end of said cross bar, a filter frame mounted at the other end of said cross bar and a. covel mounted on said cross bar adapted to fit over said members and to cut off lateral and upward radiations without intercepting radiation in the desired direction.

2. A medical arc lamp comprising a standard, an electrode support mounted at the top of said standard, electrode carrying members slidably mounted on said support, a cross bar on said standard set at right angles to said support, a reflector mounted at one end of said cross bar, a filter frame mounted at the other end of said cross bar and a cover mounted on said cross bar in the form of a roof with sloping sides adapted to fit over said members and to cut off lateral and upward radiations without intercepting radiation in the desired direction.

3. A medical arc lamp comprising a standard, an electrode support mounted at the top of said standard, electrode carrying members slidably mounted on said support, a cross bar on said standard set at right angles to said support, a reflector mounted at one end of said cross bar, a filter frame mounted at the other end of said cross bar, a cover mounted on said cross bar in the form of a roof with sioping sides adapted to fit over said members and to cut off lateral and upward radiations without intercepting radiation in the desired direction and insulated edge pieces adapted to protect those portions of said cover which may come into contact with live parts of the lamp.

4;. A medical arc lamp comprising a standard, an electrode support mounted at the top of said standard, electrode carrying members slidably mounted on said support, a cross bar on said standard set at right angles to said support, a reflector mounted at one end of said cross bar, a filter frame mounted at the other end of said cross bar, a cover mounted on said cross bar in the form of a roof with sloping sides adapted to fitover said members and to cut off lateral and upward radiations without intercepting radiation in the desired direction said sloping sides having openings glazed with a glass adapted to transmit light rays but to cut off harmful radiation.

5. A medical arc lamp comprising a standard, an electrode support mounted at the top of said standard, electrode carrying members slidably mounted on said support, a cross bar on said standard set at right angles to said support, a reflector mounted at one end of said cross bar, a filter frame mounted at the other end of said cross bar and a cover mounted on said cross bar in the form of a roof with sloping sides adapted to fit over said members and to cut off lateral and upward radiations without intercepting radiation in the desired direction, said cover having a light trapped ventilating opening at the top.

6. A medical arc lamp of the type set forth comprising a standard, a tubular cross member mounted at the top of said standard, electrode carrying members slidably mounted on said tubular cross member, a cross bar on said standard set at right angles to said tubular member, a reflector mounted at one end of said cross bar, a filter frame mounted at the other end of said cross bar, a cover mounted on said cross bar in the form of a roof with sloping sides adapted to fit over said mem bers and to cut off lateral and upward radiations without intercepting radiation in the desired direction and insulated edge pieces attached to edges of said sloping sides adapted to protect those portions of the cover which may come into contact with live parts of the lamp, said cover having openings in its sloping sides glazed with a glass adapted to transmit light rays but to cut off harmful radiation and light trapped ventilating openings at the top.

In testimony whereof I have signed my name to this specification.

WILLIAM HUGH CLIFFORD. 

